NbO_(x)掺杂对Pt/TiO_(2)催化燃烧氯乙烯的促进作用  

Promotion effects of NbO_(x) doping to Pt/TiO_(2) on catalytic combustion of vinyl chloride

作　　者：高奕吟 付睿 王丽[1] 郭耘[1] GAO Yiyin;FU Rui;WANG Li;GUO Yun(Research Institute of Industrial Catalysis,School of Chemistry and Molecular Engineering,East China University of Science and Technology,Shanghai 200237,China)

机构地区：[1]华东理工大学化学与分子工程学院,工业催化所,上海200237

出　　处：《化工学报》2022年第10期4429-4437,共9页CIESC Journal

基　　金：国家自然科学基金项目(21976057);上海市科委“科技创新行动计划”项目(19DZ1208000)。

摘　　要：通过制备Pt/Nb_(x)/TiO_(2)研究了NbO_(x)在催化燃烧氯乙烯中的作用;采用XRD、XPS、H_(2)-TPR、NH_(3)-TPD与Py-FT-IR表征了NbO_(x)对于催化剂组织结构、氧化还原以及酸碱性的影响。负载NbO_(x)可促进Pt/TiO_(2)反应性能的提高,当Nb/Ti摩尔比为0.09时,即Pt/Nb_(0.09)/TiO_(2)可在246℃实现90%氯乙烯的转化;与Pt/TiO_(2)相比,达到相同转化率的温度向低温偏移69℃。NbO_(x)也影响了催化燃烧过程中的含氯副产物的总浓度和分布。催化剂表征结果发现NbO_(x)的引入可进一步增加Pt与载体(TiO_(2))之间的相互作用,提高催化剂的表面活性氧物种的浓度,进而促进了催化剂氧化还原性能的提高。催化剂表面的总酸量随着NbO_(x)含量的增加而降低,尤其是表面Lewis酸量。因此,催化剂表面的酸量和酸分布不是决定反应性能的唯一因素,而低温的氧化还原性更有利于催化剂性能的提高。The role of NbO_(x) in catalytic combustion of vinyl chloride(VC)was studied by preparing Pt/Nb_(x)/TiO_(2).XRD,XPS,H_(2)-TPR,NH3-TPD and Py-FT-IR were used to characterize the effects of NbO_(x) on the catalyst structure,redox and acidity.The activity results presented that the presence of NbO_(x) significantly promoted reaction activity of Pt/TiO_(2),and the T90 was 246℃over Pt/Nb0.09/TiO_(2) with the molar ratio of Nb/Ti at 0.09 for vinyl chloride catalytic combustion.Compared with unmodified Pt/TiO_(2) catalyst,the value of T90 shifted to lower temperature by 69℃.The existence of NbO_(x) also affected the total concentration and distribution of chlorinated by-products during VC catalytic combustion.The characterization results illustrated that the introduction of NbO_(x) further increased the interaction between Pt and support(TiO_(2))and the concentration of surface active oxygen species on the catalyst surface which promoted the redox ability of the catalyst.The total acid amount decreased with the increase in NbO_(x) content,especially the Lewis acid amount.Hence,the total acid amount and acid distribution was not the key factor to affect the activity.The redox property at low temperature played an important role in the increase of activity.

关 键 词：催化剂 氧化 催化剂载体 氯乙烯 二氧化钛 Pt基催化剂 Nb改性 

分 类 号：TQ139.2[化学工程—无机化工]